Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published March 2014 | Submitted
Journal Article Open

Performance of the Caltech Submillimeter Observatory Dual-Color 180-720 GHz Balanced SIS Receivers

Abstract

In this paper, we report on balanced SIS receivers covering the astronomical important 180-720 GHz submillimeter atmospheric window. To facilitate remote observations and automated spectral line surveys, fully synthesized local oscillators are employed. High-current-density Nb-AlN-Nb superconducting-insulating-superconducting (SIS) tunnel junctions are used as the mixing element. The measured double-sideband (DSB) 230 GHz receiver noise temperature, uncorrected for optics loss, ranges from 50 K at 185 GHz, 33 K at 246 GHz, to 51 K at 280 GHz. In this frequency range the mixer has a DSB conversion gain of 0 ±1.5 dB. The measured 460 GHz double-sideband receiver noise temperature, uncorrected for optics loss, is 32 K at 400 GHz, 34 K at 460 GHz, and 61 K at 520 GHz. Similar to the 230 GHz balanced mixer, the DSB mixer conversion gain is 1 ±1 dB. To help optimize performance, the mixer IF circuits and bias injection are entirely planar by design. Dual-frequency observation, by means of separating the incoming circular polarized electric field into two orthogonal components, is another important mode of operation offered by the new facility instrumentation. Instrumental stability is excellent supporting the LO noise cancellation properties of the balanced mixer configuration. In the spring of 2012 the dual-frequency 230/460 SIS receiver was successfully installed at Caltech Submillimeter Observatory (CSO), Mauna Kea, HI, USA.

Additional Information

© 2013 IEEE. Manuscript received August 03, 2013; revised October 25, 2013; accepted November 18, 2013. Date of publication February 19, 2014; date of current version March 04, 2014. This work is supported in part by National Science Foundation (NSF) under Grant AST-0838261. The authors wish to thank J. Groseth and D. Warden, California Institute of Technology, Pasadena, CA, USA, for the assembly of the needed bias electronics; Prof. S. Weinreb, Jet Propulsion Laboratory and California Institute of Technology, for making available the cryogenic low noise MMIC's; Dr. J. Pierson of the Jet Propulsion Laboratory for his assistance with the medium power amplifiers modules; Prof. P. Goldsmith of the Jet Propulsion Laboratory for his advice on instrument stability and general support; and Prof. J. Zmuidzinas of the California Institute of Technology for providing the K_ɑ-band synthesizers, the wideband fast Fourier transform spectrometers (FFTS), and for his advise and physics insight over the years.

Attached Files

Submitted - 1402.1223v1.pdf

Files

1402.1223v1.pdf
Files (13.5 MB)
Name Size Download all
md5:2449f2a376a3e2fface397c618f58c7f
13.5 MB Preview Download

Additional details

Created:
August 19, 2023
Modified:
October 25, 2023